Dear All,

The Santa Monica is back to live but not that alive as I wanted it to be.
First the Battery is as dead as a doornail but with some additional help from my car we made it run. Run up to 2000 rpm but not at all with the engine taking up the trottle opening. The bike runs on 2 cilinders but the engine will stop when I am trying to open the trottle.

The ignition and all the components are the 1988 stuff but it was working 13 years ago so for me a starting point as reference. I really put real attention into timing the ignition at TDC of the horizontal cilinder so its either the Battery, The ignition bits and pieces should work since I have sparks and 2 cilinders alive so what about the carb? I ultrasonic cleaned it and bought new jet's so what else can I check the comming day's.....

Really want to make it run proper enough since I want to take it with me to Spa in 2 weeks time. Maybe you have some ideas or experiences similar.

Thanks,

Ron

I had the same electrical problem with my TT900SS recently. It would start fine, idle, and run to the 2000-3000 range, and then suddenly quit when I gave it more throttle. In checking the timing the H cylinder was firing and OK at idle, but it would not advance at any RPM. Turns out the two red/white wires to the Horizontal ignition box were reversed; I think the set of pickups came that way, but not sure. Check both cylinders and see if something like that is happening. Otherwise, it may be the dreaded chase for some electrical gremlin. MikeV

PS: I spent hours "barking up the wrong tree" before I spotted this.

Hi Mike,

I have high hopes of the fresh battery but that is a good direction to search into, thanks for that. I relied on a vague signage written on the wires 12 years ago. They hardly where readable! Will be wrenching again this friday, stay tuned.

Regards, Ron

Hello Ron Bike is looking good. I second Mikes suggestion to check the pick-up wiring. Polarity must be correct or it advances in reverse! I also had a bike that had one pick-up paired lead split to different control boxes! It actually ran but not very well.
-Cranky-

Hi Crancy and Mike,

There is a fresh battery in it and the wiring is fully checked and I am sure its good. Yet there is no improvement ! I have excluded everything so far of all the other possible couses so I am guessing the carburators are not working proper. These have been fully cleaned in an ultrasonic bath, got new jets but there might be an effect in the working.

The Idling up to 1500 rpm is fine on 2 cilinders but when opening up the gas the engine dies with spitting through the inlets ... Just brought the Dellorto Guide for carburators to study at home this weekend and they say the carb has 4 stages in operation. Idling works fine up to 1500 rpm then the low speed and progression stage is where the engine dies. I tried to run every cilinder seperate but both show the same result so both carbs have the same issue in my opinion. I also saw the acceleration pumps are not working so I need to prime the pumps but have to figure it out.

Am I going the right direction there? Or am I missing something

Going to have a good read and ponder on it, brought one of the carbs home to follow the theory....

Cheers, Ron


the accelerator pumps also not work so besides the idling the progression

I disconnect, or don't have, the accelerator pumps on my carbs/bikes. They do well without them. I don't think that is the problem.

Q: If you can't get it above 1500 RPM are you sure the ignition is advancing?

Q: Are the cams retarded (a lot) from specs?

MikeV

Hi Mike,

I realize the pumps are not the cause, the engine is standard spec Santa Monica, the cams too.
How can I find out if and how the ignition is advancing?

Regards, Ron

Ron. You will need to use an automotive strobe lamp to check this, using the procedures shown on Page M.15 of the 750 Montjuich/ 750 F1 shop manual. The Haynes 750-900 manual also shows this. You really need someone else to help by holding and twisting the throttle while this is done. Interesting that the advance to over 32 degrees at 4500 RPM from only 6 degrees at idle starts at around 1700 RPM. MikeV

So when the trouble start at 1500 rpm we might just look at the right issue
No time today, will buy a stroboscope tomorrow. Thanks

maybe, or it could just be coincidence. still good to try so this possible problem might be eliminated. it might be called a "timing light" at the store. MikeV